ip2region is an offline IP geolocation library that supports both IPv4 and IPv6 address lookups with microsecond-level query performance.
The tool solves the problem of determining geographic location from IP addresses without requiring external API calls or network connectivity. It uses a custom xdb binary format that compresses IP ranges and their associated region data, enabling fast lookups even when querying directly from disk. The library includes pre-built data files mapping IP addresses to country, province, city, ISP, and ISO country codes, with Chinese region names for China and English names elsewhere. Users can also customize the region data format to include additional fields like GPS coordinates or postal codes for their specific needs.
Developers should choose ip2region for applications requiring offline geolocation with minimal latency and no external dependencies. It suits projects that need to process high volumes of IP lookups, such as log analysis, traffic filtering, or user analytics. The tool is particularly valuable when network calls to geolocation services are impractical or when data privacy requires keeping lookups local. The project provides query client implementations across multiple programming languages, making integration straightforward regardless of the application's tech stack.
The project maintains active development with regular updates to IP data and consistent refinement of the xdb format. Query implementations are kept synchronized across different language bindings to ensure consistent behavior. The data management framework receives ongoing attention, with improvements to compression and deduplication algorithms. Documentation is maintained in multiple languages to serve a broad user base.
